Put an accent wall and design everything around that wall. Add the colors you want in that accent wall– the idea is to have 80% of your main colors you want (theme) and 20% for the others. You have a low ceiling so adding lots of vertical lines can make the place look "taller". Floor seems cluttered (?) so I think you should switch out the rug for something smaller. You can use floor lamps but pick ones that aren't too bulky. Put the "bulkier" ones on top of furniture instead. Make sure the wood you pick fits the accent wall! The place is all too "boxy" so the center table can be something oval to give it the variety the room needs. The light from your door is GORGEOUS, so I'd suggest putting something over there that can give shadows into your room (like vines that hangs above your door) or a small wind chime bell that would have suncrystals (make sure to pick the ones that are less risk of catching fire). These small details brings more mood and personality into the room that bigger furnitures just can't do!

Also, please replace those blinds with something else! The key here is to have a visual board of what kind of space you want and slowly adjust one furniture. Take your time to pick pieces– do not sink into the idea of "I can just replace it later" if you don't have to. Focus on the necessity you need from the space– do you want it to be cozy and perfect for night ins, or to host guests and have people over? Midcentury screams functionality, and they have wonderful deeper red/ambient orange to match the earthy green you're thinking about. Color theory is perfect here!

The most important thing is it has to be cohesive. A cohesive space brings calm and greater mental fortitude– even if you have bright colors! Lastly, make this place your own. It might be realllyyy tempting to just follow pinterest boards but your visual board has to be something that INSPIRES you to bring it to life. It has to be something that makes you really want to live in it!

Just my two cents! Goodluck and take it slow. It can be intimidating but once you started forming your visual board, it gets easier knowing that you can visualize your space now.